From 9ad21182a8e0df8161b064ddf116e73a98bd2096 Mon Sep 17 00:00:00 2001
From: Siavash Sameni <manwe@MacBook-Air.local>
Date: Fri, 27 Mar 2026 18:29:00 +0400
Subject: [PATCH] =?UTF-8?q?fix:=20web=20audio=20playback=20quality=20?=
 =?UTF-8?q?=E2=80=94=20gapless=20scheduling=20+=20sample=20rate=20debug?=
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- Schedule each playback buffer to start exactly where the last ended
  (was causing gaps/overlaps with fixed 60ms offset)
- Log AudioContext sample rate to console for debugging
- Reset playback timeline when falling behind

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 crates/wzp-web/static/index.html | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/crates/wzp-web/static/index.html b/crates/wzp-web/static/index.html
index 8c3bcc1..f3c6313 100644
--- a/crates/wzp-web/static/index.html
+++ b/crates/wzp-web/static/index.html
@@ -127,6 +127,8 @@ function stopCall() {
 
 function startAudioCapture() {
   audioCtx = new AudioContext({ sampleRate: SAMPLE_RATE });
+  console.log('AudioContext sampleRate:', audioCtx.sampleRate);
+  setStatus('Connected — mic active (sample rate: ' + audioCtx.sampleRate + 'Hz)');
   const source = audioCtx.createMediaStreamSource(mediaStream);
 
   // ScriptProcessorNode requires power-of-2 buffer. We use 1024 and
@@ -171,10 +173,11 @@ function startAudioCapture() {
   scriptNode.connect(audioCtx.destination);
 }
 
+let nextPlayTime = 0;
+
 function playAudio(pcmInt16) {
   if (!audioCtx) return;
 
-  // Convert int16 to float32
   const floatData = new Float32Array(pcmInt16.length);
   for (let i = 0; i < pcmInt16.length; i++) {
     floatData[i] = pcmInt16[i] / 32768.0;
@@ -187,9 +190,14 @@ function playAudio(pcmInt16) {
   source.buffer = buffer;
   source.connect(audioCtx.destination);
 
-  // Schedule playback with small buffer to reduce latency
-  const playTime = audioCtx.currentTime + 0.06; // 60ms buffer
-  source.start(playTime);
+  // Schedule seamlessly: each buffer starts exactly where the last one ended
+  const now = audioCtx.currentTime;
+  if (nextPlayTime < now) {
+    // Fell behind — reset with small lookahead
+    nextPlayTime = now + 0.04; // 40ms initial buffer
+  }
+  source.start(nextPlayTime);
+  nextPlayTime += buffer.duration;
 }
 
 function startStatsUpdate() {